Tropospheric vertical profiles of aerosol properties in the eastern Mediterranean region in summer 2001 (MINOS campaign)

Andreas Minikin1, Nikos Mihalopolous2, Constantina Economou2, Jean Sciare3, Johannes Schneider4, Zev Levin5, Amit Teller5, Eliezer Ganor5, Claudia Stein1, Harald Berresheim6, Marian de Reus4, Phil Rasch7, George Chourdakis8, and Alexandros Papayannis8

1 DLR, Institute of Atmospheric Physics, Oberpfaffenhofen, Germany
2 University of Crete, Environmental Chemical Processes Laboratory, Heraklion, Greece
3 LSCE, Gif/Yvette Cedex, France
4 Max Planck Institute for Chemistry, Mainz, Germany
5 Tel Aviv University, Department of Geophysics and Planetary Science, Ramat Aviv, Israel
6 Deutscher Wetterdienst, MOHP, Hohenpeißenberg, Germany
7 National Center for Atmospheric Research, Climate Modeling Section, Boulder, Colorado, USA
8 National Technical University of Athens, Applied Physics Department, Zografou, Greece


The MINOS project (Mediterranean INtensive Oxidant Study) aims at the understanding of the characteristics and origin of the summer time atmospheric pollution observed in the Eastern Mediterranean region. As part of the MINOS measurement campaign in August 2001 various aerosol properties were measured at ground level in Finokalia, Crete, and from two aircraft platforms, the DLR Falcon 20 jet aircraft (14 measurement flights covering the altitude range 0-12 km), and an Israelian King Air turboprop aircraft (4 flights, 0-4 km). This contribution focuses mainly on results obtained from the measurements on board the Falcon which was carrying two condensation nuclei counters (cut-off diameters of 5 nm and 14 nm), a particle absorption photometer, an integrating nephelometer and a filter sampling unit for chemical analysis of aerosol bulk samples by ion chromatography. Aerosol size distribution measurements covering the accumulation mode size range are available only for the lower troposphere from the Finokalia and the King Air measurements. Condensation particle vertical profiles show the presence of a distinct main aerosol layer with high number concentrations (1000...3000 cm-3) in the lower troposphere (typically below 2500 m). In this layer ultrafine particles below 14 nm particle diameter are absent in spite of high sulfur dioxide, OH and H2SO4 concentrations, most likely because of high aerosol surface area density. The aerosol absorption coefficient in the lower tropospheric aerosol layer is typically in the range 10...20 x 10-6m-1 and usually below detection limit in the free troposphere. However, slightly elevated absorption has been observed occasionally in the upper troposphere which appears to be connected to air originating from the Monsoon region of South East Asia. We will further discuss the observed profiles in connection to the Finokalia ground measurements and to extinction profiles measured by lidar on the greek mainland. The observational aerosol data will also be compared to predictions of aerosol optical depths from the MATCH aerosol transport model.